scholarly journals Structural properties of nuclei with semi-magic number N(Z) = 40

Author(s):  
R. Sharma ◽  
A. Jain ◽  
M. Kaushik ◽  
S. K. Jain ◽  
G. Saxena

In this paper, various ground state properties are explored for full isotonic(isotopic) chain of neutron number N [Formula: see text]proton number [Formula: see text] using different families of Relativistic Mean-Field theory. Several properties, such as nucleon separation energies, pairing energies, deformation, radii and nucleon density distributions, are evaluated and compared with the experimental data as well as those from other microscopic and macroscopic models. [Formula: see text] isotonic chain presents ample of support for the neutron magicity and articulates double magicity in recently discovered [Formula: see text]Ca and [Formula: see text]Ni. Our results are in close conformity with the recently measured value of charge radius of [Formula: see text]Ni [S. Kaufmann et al., Phys. Rev. Lett. 124 (2020) 132502] which supports the [Formula: see text] magicity. Contrarily, Zr isotopes ([Formula: see text]) display variety of shapes leading to the phenomenon of shape transitions and shape co-existence. The role of 3s[Formula: see text] state, which leads to central depletion if unoccupied, is also investigated. [Formula: see text]S and [Formula: see text]Zr are found to be doubly bubble nuclei.

2004 ◽  
Vol 13 (07) ◽  
pp. 1519-1524 ◽  
Author(s):  
VERÔNICA A. DEXHEIMER ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
MOISÉS RAZEIRA ◽  
MANFRED DILLIG

For the nuclear many body problem at high densities, formulated in the framework of a relativistic mean-field theory, we investigate in detail the compression modulus of nuclear matter as a function of the effective nucleon mass. We include consistently in our modelling chemical equilibrium as well as baryon number and electric charge conservation and investigate properties of neutron stars. Among other predictions we focus on the dependence of the maximum mass of a sequence of neutron stars as a function of the compression modulus and the nucleon effective mass.


2000 ◽  
Vol 15 (29) ◽  
pp. 1789-1800 ◽  
Author(s):  
A. R. TAURINES ◽  
C. A. Z. VASCONCELLOS ◽  
M. MALHEIRO ◽  
M. CHIAPPARINI

We investigate static properties of nuclear and neutron star matter by using a relativistic mean field theory with parametrized couplings. With a suitable choice of mathematical parameters, the couplings allow one to reproduce results of current quantum hadrodynamics models. For other parametrizations, a better description of bulk properties of nuclear matter is obtained. The formalism is extended to include hyperon and lepton degrees of freedom, and an analysis on the effects of the phenomenological couplings in the fermion populations and mass of neutron stars is performed. The results show a strong similarity between the predictions of ZM-like models and those with exponential couplings. We have observed in particular an extreme sensibility of the predictions of these theories on the specific choice of the values of the binding energy of nuclear matter and saturation density. Additionally, the role of the very intense scalar meson mean field found in the interior of neutron stars in the screening of the nucleon mass is discussed.


Author(s):  
Ajeet Singh ◽  
A Shukla ◽  
M K Gaidarov

Abstract In the present work, we have studied the alpha-like clusters (8Be, 12C, 16O, 20Ne, and 24Mg) decay half-lives in the trans-tin region for (106-116Xe, 108-122Ba, 114-124Ce, and 118-128Nd) and in transition metal region for (156-166Hf, 158-172W, 160-174Os, 166-180Pt, and 170-182Hg) nuclei. These half-lives have been calculated using the shape parametrization model of cluster decay in conjunction with the relativistic mean-field (RMF) model with the NL3* parameter set. Thus calculated cluster decay half-lives are also compared with the half-lives computed using the latest empirical relations, namely Universal decay law (UDL) and the Scaling Law given by Horoi et al.. From the calculated results, it has been observed that in the trans-tin region, the minimum cluster decay half-lives are found at nearly doubly magic or doubly magic daughter 100Sn (Nd = 50, Nd is the neutron number of the daughter nuclei) shell effect at Nd = 50 and in transition metal region, half-lives are minimum at Nd = 82, which is a magic number. Further, the Geiger-Nuttal plots of half-lives showing Q dependence for different alpha-like clusters from various CR emitters that have been plotted are found to vary linearly.


2011 ◽  
Vol 20 (05) ◽  
pp. 1227-1241 ◽  
Author(s):  
M. BHUYAN ◽  
S. K. PATRA ◽  
P. ARUMUGAM ◽  
RAJ K. GUPTA

Working within the framework of relativistic mean field theory, we study for the first time the clustering structure (nuclear sub-structure) of 112–122 Ba nuclei in an axially deformed cylindrical coordinate. We calculate the individual neutrons and protons density distributions for Ba -isotopes. From the analysis of the clustering configurations in total (neutrons-plus-protons) density distributions for various shapes of both the ground and excited states, we find different sub-structures inside the Ba nuclei considered here. The important step, carried out here for the first time, is the counting of number of protons and neutrons present in the clustering region(s). 12 C is shown to constitute the cluster configuration in prolate-deformed ground-states of 112–116 Ba and oblate-deformed first excited states of 118–122 Ba nuclei. Presence of other lighter clusters such as 2 H , 3 H and nuclei in the neighborhood of N = Z, 14 N , 34–36 Cl , 36 Ar and 42 Ca are also indicated in the ground and excited states of these nuclei. Cases with no cluster configuration are shown for 112–116 Ba in their first and second excited states. All these results are of interest for the observed intermediate-mass-fragments and fusion–fission processes, and the so far unobserved evaporation residues from the decaying Ba * compound nuclei formed in heavy ion reactions.


2021 ◽  
Author(s):  
Jeet Amrit Pattnaik ◽  
M. Bhuyan ◽  
R N Panda ◽  
S K Patra

Abstract The ground-state properties such as binding energy, root-mean-square radius, pairing energy, nucleons density distribution, symmetry energy, and single-particle energies are calculated for the isotopic chain of Ca, Sn, Pb, and Z = 120 nuclei. The recently developed G3 and IOPB-I forces along with the DD-ME1 and DD-ME2 sets are used in the analysis employing the relativistic mean-field approximation. To locate the magic numbers in the superheavy region and to explain the observed kink at neutron number N=82 for Sn isotopes, a three-point formula is used to see the shift of the observable and other nuclear properties in the isotopic chain. Unlike the electronic configuration, due to strong spin-orbit interaction, the higher spin orbitals are occupied earlier than the lower spin, causing the possible kink at the neutron magic numbers. We find peaks at the known neutron magic number with the confirmation of sub-shell, shell closure respectively at N=40, 184 for Ca and 304120.


2002 ◽  
Vol 11 (01) ◽  
pp. 55-65 ◽  
Author(s):  
CHUN-YUAN GAO ◽  
QI-REN ZHANG

The binding energies per-nucleon for 1654 nuclei, whose mass numbers range from 16 to 263 and charge numbers range from 8 to 106, are calculated by the relativistic mean field theory, with finite nucleon size effect being taken into account. The calculated energy surface goes through the middle of experimental points, and the root mean square deviation for the binding energies per-nucleon is 0.08163 MeV. The numerical results may be well simulated by a droplet model type mass formula. The droplet model is therefore put on the relativistic mean field theoretical foundations.


Sign in / Sign up

Export Citation Format

Share Document